Use callbacks in SessionRestore unit tests

chrome/browser/sessions/session_restore_browsertest.cc

Index: chrome/browser/sessions/session_restore_browsertest.cc
diff --git a/chrome/browser/sessions/session_restore_browsertest.cc b/chrome/browser/sessions/session_restore_browsertest.cc
index e36de976f2e068431da392e46fe0e320c7908abe..2f091caa654ada56642dc524a74c7a276c21336f 100644
--- a/chrome/browser/sessions/session_restore_browsertest.cc
+++ b/chrome/browser/sessions/session_restore_browsertest.cc
@@ -17,6 +17,7 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/sessions/session_restore.h"
+#include "chrome/browser/sessions/session_restore_test_helper.h"
 #include "chrome/browser/sessions/session_service.h"
 #include "chrome/browser/sessions/session_service_factory.h"
 #include "chrome/browser/sessions/session_service_test_helper.h"
@@ -139,9 +140,7 @@ class SessionRestoreTest : public InProcessBrowserTest {
 
     // Create a new window, which should trigger session restore.
     ui_test_utils::BrowserAddedObserver window_observer;
-    content::WindowedNotificationObserver restore_observer(
-        chrome::NOTIFICATION_SESSION_RESTORE_DONE,
-        content::NotificationService::AllSources());
+    SessionRestoreTestHelper restore_observer;
     if (url.is_empty()) {
       chrome::NewEmptyWindow(profile, chrome::HOST_DESKTOP_TYPE_NATIVE);
     } else {